The applications for human chemical sense analogs are just awesome. Better bomb detection. Less invasive medical tests. I have read it might even be possible to develop a chemical "fingerprint" system to detect who has been at the scene of a crime based purely on the chemcial signature that wafts off of a human body.
also, i found this useful to go over before/while I read the article: Molar concentration wiki: http://en.wikipedia....r_concentration